Let's not forget RoboVM, which is free (with paid options): https://robovm.com/

I've used this before and was amazed how well it worked, particularly with libgdx: https://libgdx.badlogicgames.com/

Not affiliated with either, by the way.

Have you by any chance used JavaFXPorts? http://docs.gluonhq.com/javafxports/

No I haven't I'm afraid. But it's definitely something to look at from the RoboVM world. Bit overloaded with work at the moment unfortunately.

And just the use of the words JavaFX and iOS in the same sentence seems weird! More than happy to be proved wrong though....

RoboVM is only free for the 30 days trial.

They've changed that very recently then. It used to be free but you just didn't get interface builder support.

The other language front-ends (C# and Oxygene, their Pascal-based language) are commercial products. IMO, making the Swift front-end free indefinitely wasn't a smart business move, because now any savvy developer will just use the Swift front-end and not have to pay anything.

They could do what Qt does and charge for commercial addons. The Qt ones are pretty compelling: in-app purchases, for example.

Plus I imagine that people using the other front ends are doing it for other reasons. C# and Pascal seem like enterprise moves (for the enterprises of >2005 and <2005).

This is not going after xamarin, it's just a toy problem.

What makes the Elements compiler just a toy in your opinion?

The biggest limitation I saw was no support for the .NET base class libraries at all, which not only makes for some strange looking C# but also rules out using any of the existing 3rd party .NET libraries out there. They market this as an advantage but I'm not convinced.

What he demonstrated is basic cross compilation techniques. There is nothing new or novel about this. You are hardly going to be able to build a full future app with exclusive Swift for the android using that method without a lot of tears, sweat, blood and effort.